Soilless Grow pH Issues - WTF!?!

Gr8Xcape98

Well-Known Member
Greetings Plant Lovers,

So I'm having pH issues with in one of my plants. I've got two plants going, each in soilless mix in 3 gal smart pots. One is 65% coco coir 35% perlite and that one is going fine with runoff pH consistently between 5.8 and 6.0. HOWEVER, I ran out of coco coir for the second pot so that one is about 35% perlite, 40% coco coir and the remaining 25% is peat moss I had on hand. The runoff from that second pot is way low, around 4.8 pH. The thing that's really tripping me out is I watered it tonight with no nutes and the runoff was around 5.0 pH. So I mixed another gallon of water (again, no nutes) pH'd the water to 6.0 and gave the plant the full gallon. Low and behold, the runoff after this second gallon was EVEN LOWER! I assumed flushing the mix would help bring the pH up but it actually dropped to 4.8. What am I doing wrong? The only difference between the two pots is the one giving me issues has some peat moss mixed in - is that's what's throwing the pH off? What's the best way to get the pH back to the 5.8 - 6.2 range?

Side by Side d31.jpg The plant on the left is in the coco coir / perlite mix. The one on the right has the peat moss mixed in. They were seeded the same day. I assumed the difference in growth was due to the plants being different strains (left is indica dominant, right is sativa dominant). But now I'm thinking the whacked out pH is hampering the sativa's nute uptake.

Any insight or advice would be greatly appreciated!
 

Bud Tipps

Well-Known Member
Don't lower the water ph. Give it 7 ph water or higher if necessary to bring it down.

The plants look healthy.
 

chuck estevez

Well-Known Member
run off tells you the ph of the water that ran past your dirt collecting all kinds of stuff. don't use that as a measure, waste of time.
 

Gr8Xcape98

Well-Known Member
Don't lower the water ph. Give it 7 ph water or higher if necessary to bring it down.

The plants look healthy.
Hey Bud. Thanks for the reply. The pH of my tap water is way high, around 8.4. Is it cool to give it straight tap for the next watering, or would such a drastic pH change shock the plant? I'm glad you think the plant looks healthy. This is my first grow so I have no idea what to expect in terms of growth. The smaller plant is "80% Sativa". Would you say this pace of growth is typical for a sativa?

Thanks Bud-dy! :mrgreen:
 

Gr8Xcape98

Well-Known Member
run off tells you the ph of the water that ran past your dirt collecting all kinds of stuff. don't use that as a measure, waste of time.
What up Chuck. Thanks for the calming words. Like most first-timers, I'm probably obsessing over things that in the long run won't matter much at all. I'll try and keep my cool and enjoy the ride. :bigjoint:
 

vtmaster

Well-Known Member
well s
Hey Bud. Thanks for the reply. The pH of my tap water is way high, around 8.4. Is it cool to give it straight tap for the next watering, or would such a drastic pH change shock the plant? I'm glad you think the plant looks healthy. This is my first grow so I have no idea what to expect in terms of growth. The smaller plant is "80% Sativa". Would you say this pace of growth is typical for a sativa?

Thanks Bud-dy! :mrgreen:
well sativas are more prone to or rather more sensitive to changes than indica....a little extra tweek n u can see the plant problems...i had one pure indica(kush) n one pure sativa(kerela gold)...cuz m frm india ..n when i added a little excess of DAP( di ammonium phosphate) npk 20-40-0 to both ...my sativa plant had tip burns the very next day whereas indica seemd pretty strong !!..so yeah do it a bit gradually .....n wel usually the plant which grows smaller is indica cuz sativa grows tall n hv vry thin leaves ur seems more lik indica
 

phil k

Well-Known Member
im not seeing a ph issue


Greetings Plant Lovers,

So I'm having pH issues with in one of my plants. I've got two plants going, each in soilless mix in 3 gal smart pots. One is 65% coco coir 35% perlite and that one is going fine with runoff pH consistently between 5.8 and 6.0. HOWEVER, I ran out of coco coir for the second pot so that one is about 35% perlite, 40% coco coir and the remaining 25% is peat moss I had on hand. The runoff from that second pot is way low, around 4.8 pH. The thing that's really tripping me out is I watered it tonight with no nutes and the runoff was around 5.0 pH. So I mixed another gallon of water (again, no nutes) pH'd the water to 6.0 and gave the plant the full gallon. Low and behold, the runoff after this second gallon was EVEN LOWER! I assumed flushing the mix would help bring the pH up but it actually dropped to 4.8. What am I doing wrong? The only difference between the two pots is the one giving me issues has some peat moss mixed in - is that's what's throwing the pH off? What's the best way to get the pH back to the 5.8 - 6.2 range?

View attachment 3437226 The plant on the left is in the coco coir / perlite mix. The one on the right has the peat moss mixed in. They were seeded the same day. I assumed the difference in growth was due to the plants being different strains (left is indica dominant, right is sativa dominant). But now I'm thinking the whacked out pH is hampering the sativa's nute uptake.

Any insight or advice would be greatly appreciated!
 

phil k

Well-Known Member
ph issues will show :
High ph: thinning leaves and curling like long fingernails
Low ph: you'll see a very light tan burn on the sides of the leaves generally it will be lightly flexible and not crispy.

yours look fine
 

a mongo frog

Well-Known Member
ph issues will show :
High ph: thinning leaves and curling like long fingernails
Low ph: you'll see a very light tan burn on the sides of the leaves generally it will be lightly flexible and not crispy.

yours look fine
I know you hate me, however good and interesting post!!! Some pics of what you explained would be a really helpful indication tool.
 

phil k

Well-Known Member
I know you hate me, however good and interesting post!!! Some pics of what you explained would be a really helpful indication tool.
why would i hate anyone... if i hate people for personal opions and beliefs i dont think i would like half the people in the world.. I'm not that kinda person. nor do i hold grudges....... i just was at a house yesterday where there was a ph pen that went bad and he was feeding 7.6 i should have taken pics cause his phone sucks he can't get me good pictures... but i see it all the damn time like once a month.. the thinning of the leafe is something that has to be seen by the grower its a bit harder to see if you didn't know what it was like healthy.. the acidic feeding is really easy to spot when you see it.. its almost like a toast color but instead of it being crispy and crumbly the burnt part generally is lightly flexible like its still healthy. ill take pics and post them next time.
 

phil k

Well-Known Member
that guys bulb on his ph pen cracked and he didn't know it.. he was feeding like 5.2 for like 2 weeks before he noticed it.
 

Gr8Xcape98

Well-Known Member
a helpfull ph chart for you to use View attachment 3438013
Hey Ugorg. Thanks for posting that chart. I've seen it before and heard soilless mix should be treated more like hydroponic. I've been aiming for a pH of about 6.0 since it seems like a safe "sweet-spot". As I mentioned before, the pH of the pot will only perlite and coco coir is rock steady. It's the pot with some peat moss mixed in that's giving me issues. That said, the consensus seems to be that the plants looks healthy, so I'll take a chill pill. 8)
 

Gr8Xcape98

Well-Known Member
heres ph burn from the ph being too acidic.. see how the burns only on the sides when it starts and is very light tan in color..View attachment 3438694
Hey Phil. Thanks for posting those pics, that helps a lot! No, I don't have any leaves that have REAL signs of stress. There are a few leaves with a few tan dots on the side edges, but nothing extreme like either of the pictures you posted. An earlier reply by Chuck said that runoff can give a "false" pH reading since the runoff water has all kids of crap in it due to having filtered through the soil. I'm guessing there's something about the peat moss that's throwing off the pH of my runoff.

That said, the Sativa has actually grown considerably in the last couple days. The growth spurt has calmed me down some. The ladies will be switched to 12/12 on tomorrow, which brings up another question. What's your feelings on KoolBloom? Is it a must have? Or is it trouble waiting to happen? I'm thinking of ordering some for the flower phase.

Thanks Dr. Phil :mrgreen:
 

Gr8Xcape98

Well-Known Member
well s

well sativas are more prone to or rather more sensitive to changes than indica....a little extra tweek n u can see the plant problems...i had one pure indica(kush) n one pure sativa(kerela gold)...cuz m frm india ..n when i added a little excess of DAP( di ammonium phosphate) npk 20-40-0 to both ...my sativa plant had tip burns the very next day whereas indica seemd pretty strong !!..so yeah do it a bit gradually .....n wel usually the plant which grows smaller is indica cuz sativa grows tall n hv vry thin leaves ur seems more lik indica
Hey VTMaster. Thanks for the insight. Being a first timer, I decided to grow both an indica dominant and sativa dominant to get some exposure to both and see how each grows. I have to say, the indica has been MUCH better behaved and seems to be easier to grow. That said, the Sativa has actually grown quite a bit since I initially started this thread. As I mentioned in an earlier reply, the plant doesn't have many "burns" on the leaves, so I may have been over-reacting. Both plants will be transitioned to the flowering phase this weekend. Compared to the indica, the sativa looks very small. It's only about 7" tall and not very wide. The indica is about the same height, but only due to LST'ing, and it's about 18" wide. I just want to get through this first grow without harming the plants and learn all I can. The next grow I'll aim to totally max out the yield! :weed:
 

vtmaster

Well-Known Member
Hey VTMaster. Thanks for the insight. Being a first timer, I decided to grow both an indica dominant and sativa dominant to get some exposure to both and see how each grows. I have to say, the indica has been MUCH better behaved and seems to be easier to grow. That said, the Sativa has actually grown quite a bit since I initially started this thread. As I mentioned in an earlier reply, the plant doesn't have many "burns" on the leaves, so I may have been over-reacting. Both plants will be transitioned to the flowering phase this weekend. Compared to the indica, the sativa looks very small. It's only about 7" tall and not very wide. The indica is about the same height, but only due to LST'ing, and it's about 18" wide. I just want to get through this first grow without harming the plants and learn all I can. The next grow I'll aim to totally max out the yield! :weed:
yeah just cut down on the nutes.......even my leaf tips are brown...dats da sign u r overfeeding n u should reduce it...but it wont effect ur plant unless u rectify ....will that b a nice word?!?..ok correct ur mistake quick .....
just give it a half flush and start wid little nutes after 3-4 days ....n try using organic ..bloodmeal(N) bone meal (15%N and 40% P) and go for banana peel (47% K with other macro nutes such as Mg n Ca and filled with micro too)..i grow mine with only these 3 ....cuz i compost my soil after use ..and the budz turns out yummmyyy!!keep us updated about ur grow!!...best f luck
 

phil k

Well-Known Member
Hey Phil. Thanks for posting those pics, that helps a lot! No, I don't have any leaves that have REAL signs of stress. There are a few leaves with a few tan dots on the side edges, but nothing extreme like either of the pictures you posted. An earlier reply by Chuck said that runoff can give a "false" pH reading since the runoff water has all kids of crap in it due to having filtered through the soil. I'm guessing there's something about the peat moss that's throwing off the pH of my runoff.

That said, the Sativa has actually grown considerably in the last couple days. The growth spurt has calmed me down some. The ladies will be switched to 12/12 on tomorrow, which brings up another question. What's your feelings on KoolBloom? Is it a must have? Or is it trouble waiting to happen? I'm thinking of ordering some for the flower phase.

Thanks Dr. Phil :mrgreen:
yeah i agree with chuck.. i don't even know why people check ph run off... i can if your running like a flood system or some hydro systems that way you can see if your media is fucking up your ph.. but media like soil/promix... its pointless...
 
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